Durable Oil Buffers with Automatic Reset

ABSTRACT

This Invention publicizes a kind of oil buffers with automatic reset, aiming to provide a kind of buffers with simple structure, long service life and function of automatic compensation of oil leakage. Its technical kernel includes a cylinder and a case around the outer surface of the Cylinder, where elastic capsule for oil storage is provided between the cylinder and case and wraps outer surface of the cylinder, there are through holes to atmosphere on the case. This Invention can be applied in application of keeping speed constant, shock absorption and etc.

CROSS REFERENCE TO RELATED PATENT APPLICATION

This invention claims the priority of the Chinese patent application No. 200610124073.7 with a filing date of Dec. 7, 2006.

FIELD OF THE INVENTION

This Invention relates to buffers of pressure, especially to a kind of durable oil buffers with automatic reset.

BACKGROUND OF THE INVENTION

Structure of conventional buffers of oil pressure with automatic reset is shown FIG. 1. It consists of Cylinder 101, String 102 and Piston 103 inside the Cylinder 101, Piston Rod 104 connected with Piston 103, Sleeve Bearing 105 mounted on Cylinder 101, Seal ring 106 between Piston Rod 104 and Sleeve Bearing 105 and between Sleeve Bearing 105 and Cylinder 101, Case 107 Set on Cylinder 101, and compressible Bushing 108 between Cylinder 101 and Case 107. There are Holes 109 for oil return on wall of Cylinder 101 and a number of Orifices 110 along wall of Cylinder 101 in axial direction. Holes 109 for oil return and Check Valve 111 are provided on Piston 103. Its operating principle is as follows: In case Piston Rod 104 is pressed or impacted, it brings the Piston 103 to compress String 102 so that String 102 moves inwards. The damping effect is realized with adjusting speed of oil return in Cylinder 101 from right cavity to left cavity by Orifices 110 at different distances. The speed will change gradually from high to low and zero at the end. When external force goes out, Piston 103 under force from String 102 brings Piston Rod 104 to move outwards. In this case, the Check Valve 111 on the Piston 103 is opened, oil in Cylinder 101 may flow fast from left cavity to right cavity until the Piston returns back to its original position. There are following disadvantages for this kind of buffers: (1) It uses seal ring 106 between Piston Rod 104 and Sleeve Bearing 105 to make sealing. When Piston Rod 104 moves along a straight line, oil in Cylinder 101 will always stick on surface of Piston Rod 104 and continuous oil leakage will happen, and vacuum will finally appear in Cylinder 101 because of this leakage after a period of operation. Then the buffer will finally be discarded as useless if air is sucked into Cylinder 101, thus its service life is short; (2) It is merely partial compression of liquid and compressible bushing 108 between Cylinder 101 and Case 107 that are used to compensate for the reduction of volume due to Piston Rod's entering into Cylinder 101. In order to ensure effective travel of Piston Rod 104, diameter of Piston Rod can not be too large, therefore, rigidity of the Piston Rod 104 is low and larger impact load could not be endured and scope of its application is limited.

SUMMARY OF THE INVENTION

The technical object of this Invention is a kind of durable oil buffers with automatic reset that is of simple structure and long service life, capable of automatic compensation of oil leakage.

Technical design of this invention is as follows:

A durable oil buffer with automatic reset comprises a Cylinder with an open end and a closed end; a sleeve bearing is mounted on the open end of the cylinder, a spring is in the cylinder, a piston rod connected with a piston is located inside in the cylinder, the piston is against the spring and the piston rod passing through the sleeve bearing; a number of oil orifices are along the wall of the cylinder, an oil returning hole and a check valve are provided on the piston; an elastic capsule is around outer surface of the cylinder, and oil fills in the cylinder and elastic capsule; when the piston rod being pushed inside, the oil goes through the oil orifices into the elastic capsule and the spring being pressed, thereby buffer being achieved; when the push being released the spring pushing the piston out automatically, and the oil through the check valve and oil returning hole goes to the other end of the cylinder; If the oil leaking, the elastic capsule shrinks to compensate oil leakage, thereby vacuum in the cylinder is avoided, and the service life of the oil buffer is increased.

a case can be packaged outside of the elastic capsule for protection, a number of holes to atmosphere are provided on the case.

With above-mentioned structure of this Invention, by provision of elastic capsule for oil storage on outer surface of the Cylinder and through holes to atmosphere on the case, this Invention makes automatic compensation for oil leakage in the Cylinder by means of elasticity of elastic capsule for oil storage, and vacuum is avoided, thus makes service life of buffers longer; In addition, the expansion effect of elastic capsule for oil storage makes it possible to balance volumes of right and left oil cavities automatically. As result, it is possible to increase length of Piston Rod to increase its operating travel, or to increase diameter of the Piston Rod to increase its capacity of endurance of impact load and to expand the scope of its application.

BRIEF DESCRIPTION OF THE DRAWINGS

Following is a further detailed description of this Invention in conjunction with embodiment shown in drawings. But this description would not be construed as a limitation to this Invention.

FIG. 1 is a structural representation of a buffer of oil pressure from prior arts.

FIG. 2 is a structural representation of an embodiment for this Invention.

DETAIL DESCRIPTION OF THE INVENTION

As shown in FIG. 2, durable oil buffers with automatic reset of this Invention comprises of Cylinder 1 and Case 2 around outer surface of the said Cylinder 1, an elastic Capsule 3 for storage of oil between the said Cylinder 1 and Case 2, String 4 and Piston 5, Piston Rod 6 connected with the Piston 5, Sleeve Bearing 7 mounted on Cylinder 1, and Seal ring 8 between Piston Rod 6 and Sleeve Bearing and between Sleeve Bearing 7 and Cylinder 1. Said elastic Capsule for oil storage covers outer surface of Cylinder 1, and there are two through holes 2 a to atmosphere on Case 2. Holes 1 a of oil return on wall of Cylinder 1 and a number of Orifices 1 b along wall of Cylinder 1 in axial direction. Holes 5 a for oil return and Check Valve 5 b are provided on Piston 5.

The operating principle of this Invention is the same as that of prior art. The difference is as follows: By provision of elastic Capsule 3 for oil storage on outer surface of the Cylinder 1 and through Holes 2 a to atmosphere on the Case 2, this Invention makes automatic compensation for oil leakage in the Cylinder 1 by means of elasticity of elastic Capsule 3 for oil storage, and vacuum is avoided, thus makes service life of buffers longer significantly; In addition, because of the expansion effect of elastic Capsule 3 for oil storage make it possible to balance volumes of right and left oil cavities automatically. As result, it is possible to increase length of Piston Rod 6 to increase its operating travel, or to increase diameter of the Piston Rod 6 to increase its capacity of endurance of impact load. 

1. A durable oil buffer with automatic reset comprising: a cylinder with an open end and a closed end; a sleeve bearing mounted on the open end of the cylinder; a spring in the cylinder; a piston rod connected with a piston located inside in the cylinder, the piston being against the spring and the piston rod passing through the sleeve bearing; a number of oil orifices along the wall of the cylinder, an oil returning hole and a check valve provided on the piston; an elastic capsule around outer surface of the cylinder, and oil being filled in the cylinder and elastic capsule; when the piston rod being pushed inside, the oil goes through the oil orifices into the elastic capsule and the spring being pressed, thereby buffer being achieved, when the push being released the spring pushing the piston out automatically, and the oil through the check valve and oil returning hole goes to the other end of the cylinder; If the oil leaking, the elastic capsule shrinks to compensate oil leakage, thereby vacuum in the cylinder is avoided, and the service life of the oil buffer is increased.
 2. The durable oil buffer of claim 1, wherein a case is packaged outside of the elastic capsule for protection, a number of holes to atmosphere are provided on the case.
 3. The durable oil buffer of claim 1, wherein a seal ring is provided between the piston rod and the sleeve bearing, a seal ring is provide between the sleeve bearing and cylinder.
 4. The durable oil buffer of claim 1, wherein the elastic capsule is made from oil-proof rubber or elastic plastic. 